Automatic train-control system



Aug. 28, 1928. 1,682,518

w. K. HOWE AUTOMATIC TRAIN CONTROL SYSTEM Origirial Filed y 24, 1919 FIG.1.

EPV

Tra-m 11 n log 109 Q Track PIC-21.2. 1

FIG. 3.

BY Z0, I/ 7% M ATTORN EY Patented Aug. 28, 1928.

v UNITED STATES PATENT OFFICE.

"ZNTHRQP K. HOWE, OF ROCHESTER, NEW YORK, ASSIGNOB TO GENERAL RAILWAY SIGNAL COMPANY, OF ROCHESTER, NEV YORK.

AUTOMATIC TRAIN-CONTROL SYSTEM.

Original application flledMay 24, 1919, Serial No. 299,438. Divided and this application filed February This invention relates to automatic train control systems for railroads, and more particularly to an established and reliable means for establishing communication between the trackway and a moving car or train inductively without physical contact between any parts on the track and on the train, so that the operation of the system will not be influenced by snow, ice, or other adverse weather conditions.

This application is a division of my prior application Ser. No. 299,488, filed May 24, 1919.

The specific objects and characteristics of the invention will appear hereinafter as the description progresses.

In the accompanying drawings, Fig. 1 illustrates in a simplified and diagrammatic manner one form of construction of the carcarried element or receiver and the cooperating trackway element, which together constitute a means for transmitting controlling impulses or indications from the trackway to a passing car or train; Fig. 2

' illustrates a modification of the car-carrier element or receiver; and Fig. 3 illustrates a modified construction of the trackway element.

Referring first to Fig. 1 of the accompanying drawing, the car-carried element is designated as a whole L,and the cooperating track element T. The car-carried element L is supported on the locomotive, car, or other railway vehicle in any suitable or convenientmann'er (not shown), preferably so as to extend cross-wise of the track and underneath the car near the center line of the track, This car-carried element L v conr prises two side members 100, of a general Z-shape in cross section, which are connected by a magnetic core 101 having thereon a coil or winding 102 normally energized from a battery or other source of current 103. To one of the side members 100, is pivotally connected to one end of an armature 104:, which is biased by a spring 105 upwardly and away from the other side member 100. This armature 104 carries an insulated contact finger 10G arranged to connect stationary contacts, with said armature in its attracted position, and maintain closed a normally energized circuit for a suitable brake control device, such as an electropneumatic valve EPV. A suitable construction of this electro-pneumatic Serial No. 251,583.

valve EPV, and automatic brake applying means controlled thereby, is illustrated in the parent application.

The traclnvay element- T comprises, a U- shaped magnetic core 110, with enlarged pole pieces, and coils or windings 109 on each leg, of said core.- These coils 109 are included in series in a die-energized circuit of (preferably) low resistance controlled by a relay 0, so that when said relay is energized, said coils are included in a low resistance (lo-energized circuit, and when said relay is de energized, said coils are on open circuit. It is contemplated that the relay 6 will be automatically controlled in accordance with traflic' conditions in some suitable way, such as shown, for example, in my prior application above mentioned. This tract: clement T* is suitably supported on made as short as practical clearances on railroads will safely permit. The size and proportion of the various parts are of course selected to obtain the desired operation with the air-gap selected.

Normally, while the car is traveling between the control points where the trackway elements T* are located, the uni-directional flux produced by the energized coil 102 retains the armature 104 against the usual residual pin in opposition to the spring 105, thereby maintaining closed the circuit for energizing the brake control device EPV. \Vhenthis car-carried element L? passes over a trackway element T under danger trafiic conditions, with the relay 6 de-energized and the coils 109 on open circuit, this trackway element presents in effect a magnetic loop tending to shunt out or divert flux from the armature 104. The parts are so proportioned, in accordance with well known principles, which will be readily apparent to those skilled in the art, that the core 101 is substantially saturatciand since an additional path for flux is provided by the shunt path through the trackway element T, sufficient flux is diverted from the path through the armature 104, to permit the spring 105 to overcome the attraction of the armature 104 and thus open the circuit for the EPV.

Vhen the car-carried armature L passes over a trackway element T under clear trafiic conditions, the coils 109 of said trackway element 109 being short-circuited, the flux from the energized coil 102, tending to pass through the core 110 of the trackway element, induces a current in the coils 109 which opposes or. chokes back passage of such flux, with the result that the magnetic flux 'iormally passing through the armature l-lis not sufliciently decreased to permit the spring 105 to retract said armature.

In the modified construction of the carcarried element or receiver shown inFig. 2,

sothat it is retracted by the spring 105 to open the circuit for the EPV.

The modified construction of the trackway element'I shown in Fig. 3 comprises two side members 60, angleshaped in cross section, which are connected by a magnetic core 01 surrounded by a coil (32. These side members 00 preferably extend lengthwise of the track at a suilicientdistance to influence the car-carried element for a short interval of time suitable for producing reliable operation. If desired, a number of cores 61 and coils 02 may be employed with the side members 00. The coil 02 is included in a circuit with a battery 5 and the controlling contact of a relay 6; and this coil is intended to be energized under clear trafiic conditions, and to be de-energized under danger trar'lic conditions. Under clear trafiic conditions, when the coil 62 is energized, it gives the side members 00 a polarity which opposes the polarity of the pole pieces of the car-carried element, Figs. 1 or 2, cooperating therewith. As a result, there is substantially no change in the flux passing through the armature 105% or 104 when thelcarkcarried element passes over this trackway element under clear traffic.

conditions. Under danger trailic conditions, the side members and the core 01 constitute a magnetic loop to shunt out flux from the armature 104 or 104: and cause'retraction thereof in the same way as the trackway element shown in Fig. 1.

The various modifications in the construction of the car-carried element and the trackway element, illustrated in the accompanying drawings, are merely typical and illustrative of the various forms embodying my invention, and various other constructions and combinations involving the same principles and characteristics will be readily apparent to those skilled in the art. I desire it to be understood, therefore, that the constructions illustrated do not exhaust the various modifications which may he made in accordance with my invention.

Furthermore, it is obvious that the various types of impulse transmitting means herein disclosed may be used with various forms of train control or brake governing appliances, and I desire to have it understood that my invention in this, as in'many other respects, is not limited to the precise constructions and combinations of various devices illustrated and described.

hat I claim as new and desire to secure by Letters Patent of the United States, is:-

1. In an automatic train control system for railroads, a car-carried element having two magnetic side members connected by a core at an intermediate point, a biased movable armature cooperating with the upper ends of said side members and havingcontacts opened when said armature is retracted, an energized coil on said core producing flux for holding said armature in its attracted position, a trackway element having a core constituting a partial magnetic circuit for bridging the lower ends of said side memhers and thereby acting to shunt flux from said armature and cause retraction thereof, a winding on the core of the trackway element, and means for at times including said winding in a tie-energized circuit of low resist-- ance and at other times placing said winding on open circuit.

2. Impulse transmitting means for automatic tain control systems comprising, a car-carried receiver having a magnetic circuit energized with uni-directiomil flux. an armature included in said circuit and biased to a retracted position, contacts operated by said armature and closed only if it is attracted, a trackway element having a magnetic core arranged to provide a partial magnetic circuit to shunt flux from said armature, a. winding on said core of the trackway element, and a controllable means for at times including said winding in a closed deenergized circuit of low resistance to oppose the passage of flux through said core and for placing said winding on open circuit at other times.

In testimony whereof I aflix my signature.

IVINTHROP K. HOWE. 

